<div class="easyui-layout" id="form-formula" style="height: 410px;">
    <div data-options="region:'north'" style="height:88px" class="editor-group">
        <a href="#" class="easyui-menubutton"
            data-options="menu:'#mm1',iconCls:'icon-large-picture',size:'large',iconAlign:'top'">常用</a>
        <a href="#" class="easyui-menubutton"
            data-options="menu:'#mm1',iconCls:'icon-large-picture',size:'large',iconAlign:'top'">常用</a>
        <a href="#" class="easyui-menubutton"
            data-options="menu:'#mm1',iconCls:'icon-large-picture',size:'large',iconAlign:'top'">常用</a>
        <a href="#" class="easyui-menubutton"
            data-options="menu:'#mm1',iconCls:'icon-large-picture',size:'large',iconAlign:'top'">常用</a>
    </div>
    <div data-options="region:'center'," style="background-color: #bebdbd;">
        <input type="text" style="width:1px;height:10px;position: absolute;left:0px;top: 0px;z-index: -1;">
        <canvas width="780" height="300" style="background: #fff;"></canvas>
    </div>
    <div id="mm1" style="width:150px;height: 200px;">

    </div>
</div>